Development of in-situ Marine Sediment Geo-Acoustic Measurement System with Real-Time and Multi Frequencies (the Second Generation)

Compared with the laboratory acoustic measurement of sediment samples, the in-situ acoustic measurement in marine sediment is considered more accurate and rehable, because it covers all of the surrounding environment factors and avoids the disturbance during the course of sampling and transporting of sediment samples. A new multi-frequency in-situ geoacoustic measurement system （MFIS^AMS） has been developed. The system can provide acoustic vdocity （compressional wave） and attenuation profiles of the uppermost 4 - 8 m sediment in the seafloor. It consists of 8 channels with 12 frequencies （multi-frequencies） and 0.5 - 2 MHz sampling rates. The data collected can be transmiuted in real-time. Associated with inclinometer and altimeter, it can provide the data for depth emendation. Acoustic velocity and attenuation data have been obtained from two in-situ experiments conducted in the Hangzhou Bay.

In-situ stabilisation followed by ex-situ composting for treatment and disposal of heavy metals polluted sediments

An innovative in-situ stabilisation treatment followed by ex-situ sediment composting was tested for its ability to treat and dispose of heavy-metal-polluted sediments in a river near the Chinese Pearl Delta. First, polluted sediments were treated in-situ to stabilise the heavy metals. Then the treated sediments were dredged, dewatered and sent for high temperature aerobic composting （HTAC） treatment. Finally, the compost products were used as a fertiliser for fiver bank plants. The stabilisation efficiency of heavy metals during the process was investigated and the results are as follows： （1） using in-situ stabilisation, the extraction concentrations of Cu, Zn and Pb were reduced by 65.0%, 82.2% and 90.0%, respectively, which are much lower than the national standard given in the Identification Standard for Hazardous Waste （GB5085.3-1996）; （2） chemical fraction analysis showed that heavy metals were further stabilized during the HTAC treatment; （3） the concentrations of Cu, Zn and Pb in rainwater leachate through the river bank met the level of class V in the Environmental Quality Standards for Surface Water in China （GB3838-2002）. Therefore, using this new process, the toxicities of heavy metals in sediments were reduced markedly.

DNA REPAIR MEASURED BY NUCLEOID SEDIMENTATION TECHNIQUE AMONG MEMBERS TAKEN FROM 3 XERODERMA PIGMENTOSUM (XP) FAMILIES AND THE POSSIBILITY OF DETECTING HETEROZYGOTES

The nucleoid sedimentation test was used to analyse theDNA repair capacity in 35 members taken from 3 XerodermaPigmentosum (XP) families after their peripheral bloodlymphocytes being exposed to UV irradiation and N-methyl-N’-

Design of wear-out-failure in-situ repair parts by environment-friendly nanocopper additive

Oleic acid surface-modified Cu nanoparticles with an average size of 20 nm were prepared by liquid phase reducing reaction. The tribological performance and mechanism of nanocopper as additive were studied by means of tribotester, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and nanoindentation instrument. The results indicate that the modified nanocopper additive can significantly improve the wear resistance and reduce friction coefficient of base oil. A copper protective film is formed and contributes to the excellent tribological properties of nanocopper additive. On the basis of the film forming mechanism, a new in-situ repair method was designed and used to repair wear-out-failure injection pump plunger and barrel. Furthermore, the current research progress of nanoparticles as green energy-saving lubricating oil additives were presented.

Experimental investigation on the effective thermal conductivities of different hydrate-bearing sediments

The natural gas hydrate has been regarded as an important future green energy.Significant progress on the hydrate exploitation has been made,but some challenges are still remaining.In order to enhance the hydrate exploitation efficiency,a significant understanding of the effective thermal conductivity(ETC)of the hydrate-bearing sediment has become essential,since it directly controls the heat and mass transfer behaviors,and thereby determines the stability of hydrate reservoir and production rate.In this study,the effective thermal conductivities of various hydrate-bearing sediments were in-situ measured and studied.The impacts of temperature,particle size and type of sediment were investigated.The effective thermal conductivities of the quartz sand sediments before and after hydrate formation were in-situ measured.The results show the weak negative correlation of effective thermal conductivity of the quartz sand sediment on the temperature before and after the hydrate formation.The effective thermal conductivity of the hydrate-bearing sediment decreases with the increase of particle size of the sediment.The dominant effect of the type of porous medium on the characteristics of the effective thermal conductivity of hydrate-bearing sediment was highlighted.The results indicate that both the effective thermal conductivities of hydrate-bearing quartz sand sediment and hydrate-bearing silicon carbide sediment are weakly negatively correlated with temperature,but the effective thermal conductivity of hydrate-bearing clay sediment is weakly positively dependent on the temperature.In addition,the values of the effective thermal conductivities of various hydrate-bearing sediments are in the order of hydrate-bearing silicon carbide sediment>hydrate-bearing quartz sand sediment>hydrate-bearing clay sediment.These findings could suggest that the intrinsic thermal conductivity of porous medium could control the characteristics of effective thermal conductivity of hydrate-bearing sediment.

The controlling factors of high suspended sediment concentration in the intertidal flat off the Huanghe River Estuary

The Huanghe River(Yellow River)is known by its high suspended sediment concentration(SSC)in its river mouth tidal flat.However,the factors controlling the high SSC over there are not well understood.Therefore,we conducted 7-d hydrodynamic observations(water depth,wave height,and current velocity)and SSC measurements on the tidal flat off the Huanghe River Mouth.The data shows that in most of time,under the calm sea condition,the SSC ranges 0.1–3.5 g/L,and sediment discharge from the river is the main source.However,when hydrodynamics are enhanced in a tidal cycle and large-scale erosion occurs on the seafloor,resuspended sediment becomes the main source,and the SSC in the water column reaches 17.3 g/L.We find the suspended sediment flux is mainly controlled by the tidal current and Stokes drift,while the wave-induced shear stress could also affect the variation of suspended sediment flux.During the observation period,when sea under calm-rippled conditions,the current-induced resuspended sediment concentration(RSC)was greater than the wave-induced RSC.In contrast,in smooth-wavelet sea conditions,the wave-induced RSC was greater than the current-induced RSC,for instance,a single wave event was found to cause 11.8 cm seabed erosion within 6 h.This study reveals different controlling factors for the high SSC near a river-influenced tidal flat,and helps us get a better understanding of a delta's depositional and erosional mechanisms.

Tests of new in-situ seabed acoustic measurement system in Qingdao

A new in-situ seabed acoustic measurement system is developed for direct in-situ measurement of sediment geoacoustic properties （compressional wave velocity and attenuation）. The new in-situ system consists of two parts： the deck control unit and the underwater measurement unit. The underwater measurement unit emits sonic waves that propagate through the seafloor sediment, receives the returning signals, and transmits them to the deck control unit for waveform display and analysis. The entire operation is controlled and monitored in real time by the deck control unit on the research vessel and can provide recording of full waveforms to determine the sound velocity and attenuation. This paper outlines the design of the system, the measurement process, and demonstrates its application in tests carded out on seabed sediment off the Qingdao coast, China. The test results show that the system performed well and rapidly provided accurate in-situ acoustic velocity and attenuation estimates of the seafloor sediment.

海洋沉积物重金属检测方法及污染防治研究进展

阐述了近几年在环境、土壤、沉积物等研究领域较为常用的重金属检测方法,如:X射线荧光光谱法、电感耦合等离子体质谱法、原子吸收光度法等,对比了其优缺点,同时介绍了若干较为前沿的如:酶抑制法、电化学生物传感器法、激光诱导击穿光谱(LIBS)技术、高光谱分析技术等分析方法。分析了不同机理的沉积物重金属污染防治措施、应用范围、优缺点和研究进展;提出了在实验室条件允许的情况下,分析方法应优先选择灵敏度高且能同时进行多元素和同位素分析的电感耦合等离子体质谱法;防治措施可选择结合2种及2种以上的单一修复手段的联合修复技术。

底泥原位修复技术的应用探讨——以上海某公园为例

河湖内源污染以往采用清淤疏浚方式,但是该方式具有操作难、处置复杂、费用高等问题。为快速、安全并有效地削减河湖内源污染,减少底泥持续释放对水质及居民感观的影响,促进水质稳定达标,本文提出底泥原位修复技术,该技术具有环境友好、经济节约、安全高效的特点,并在上海某公园成功示范应用,为类似项目提供了示范参考。

多泥沙河流破损门槽埋件水下快速修复工艺研究与实践

多泥沙河流水电站的闸门门槽埋件长期受含悬移质和推移质的高速水流冲刷、磨蚀、撞击,会产生不同程度的破坏。以黄河流域某水电站水下门槽埋件修复工程为例,对水下修复的材料和工艺进行探索和总结,形成一套破损门槽埋件水下环氧混凝土快速修复十六步施工工艺,并在国内多个水电站泄水建筑物水下修复项目中推广应用。

3株芽孢杆菌对刺参池塘有机物的降解效果及鉴定

为修复刺参Apostichopus japonicus养殖池塘底质环境,根据菌株对底泥中有机质(COD)、氨氮(NH_4^+-N)和亚硝酸盐(NO_2^--N)的去除率,从刺参养殖池塘底泥和商品益生菌中筛选高效降解刺参养殖池塘底质有机污染物的潜在益生芽孢杆菌,并对筛选出的优良菌株的产酶能力和降解特性进行了研究。结果表明:从分离的11株细菌中经过筛选最终获得3株优良菌株(N1、DL、R),它们能同时高效降解底泥中COD、NH_4^+-N和NO_2^--N,5 d内对COD的最大去除率分别为45.71%、23.98%、24.97%,对NH_4^+-N的最大去除率分别为60.54%、36.15%、36.74%,对NO_2^--N的最大去除率分别为52.10%、14.41%、28.82%;根据菌株生理生化特性以及16S r DNA序列分析,N1、DL、R菌株分别为白翎芽孢杆菌Bacillus baekryungensis、地衣芽孢杆菌B.licheniformis和解淀粉芽孢杆菌B.amyloliquefaciens。本研究结果可为进一步开发高效的刺参养殖池塘底质有机污染物降解益生菌及复方制剂提供参考。

沉降地层破裂井壁修复治理工程设计原理

针对立井井壁的破坏机理 ,提出了修复治理破裂井壁的设计原则 ,同时给出了破裂井壁注浆参数的确定方法、表土层沉降量的计算方法以及卸压槽和槽钢加固结构的设计方法。应用该研究成果已成功地修复治理了 15个破裂井壁 。

汉沽污水库污染水体沉积物修复限值的确定方法

以中新天津生态城汉沽污水库修复工程为例,本文提出了包括沉积物本底调查、确定水环境管理目标、实验和引用结合确定修复限值的污染水体沉积物修复限值制定方法。通过本底调查和实验研究,汉沽污水库沉积物修复限值共确定27项指标,被分为基本项目和补充项目。其中,基本项目反映了地表水环境质量控制的需求,而补充项目则反映了水生生态系统安全。污水库沉积物修复限值的确定,为汉沽污水库的修复工程提供技术指导,同时也为国内类似大型水体修复工程提供借鉴。

黄河沙芯复合结构备防石技术优势和经济分析

针对黄河防汛抢险中采用传统备防石存在的问题,研制了黄河沙芯钢筋混凝土复合结构备防石。利用复合材料的基本原理,采用钢筋混凝土和叠层复合材料的方法,对其生产工艺进行研究,并分析其经济效益和实施可行性。结果表明:该项目经济效益良好,按年产量50万m3、项目投资500万元计,产品直接经济效益为1 646.5万元/年。该产品降低了备防石使用成本,提高了性能,可作为天然石材备防石的代用品,同时有利于黄河泥沙综合治理。

电磁效应对含SiO_2/SnO_2复合纳米粒子润滑油的摩擦自修复特性影响

用四球机考察了添加SiO_2/SnO_2复合纳米粒子的润滑油在电磁场作用下的摩擦学和自修复性能,用扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)分析了磨斑表面形貌及其典型元素的化学状态,并对抗磨自修复机理进行了初步探讨。结果表明,在磁场作用下,含SiO_2/SnO_2复合纳米粒子的润滑油润滑下的摩擦副磨斑直径和摩擦系数均比无磁场时小,且自修复效果更加明显。这是由于磁场有利于SiO_2/SnO_2复合纳米添加剂在摩擦副表面沉积,沉积物在摩擦载荷和摩擦热作用下快速熔融铺展,形成具有良好抗磨减摩和修复性能的沉积物膜。

类核沉降法对三个着色性干皮病(XP)家系成员DNA修复能力的测定及杂合子的检出

应用类核沉降法,分析了三个着色性干皮病家系中35名成员外周血淋巴细胞在紫外线(2.5μJ/mm^2)照射和MNNG(2μg/mI)损伤后DNA修复能力。结果表明,6名XP患者和9名杂合子DNA损伤后20小时尚不能完成修复,他们11小时DNA修复率均值分别为UV,0.61±0.13,0.59±0.15和MNNG,0.44±0.15,0.46±0.16,与家系中10名非血缘亲属正常人DNA修复率均值为UV,0.96±0.07,MNNG,0.71±0.07相比,差异非常显著(Ρ<0.01),而XP患者和杂合子DNA修复率则无显著性差异(Γ>0.05)。提示,类核沉降技术可能为XP家系中杂合子成员检出提供一种有希望的方法。

类核沉降法分析247例癌症病人和正常人的DNA修复能力

应用新建立的类核沉降法,分析了108例食管癌、肺癌和卵巢癌患者以及139例正常人DNA修复能力。外周血淋巴细胞受2.5μJ/mm^2紫外线照射后,大多数正常人11小时完成DNA修复,而大多数癌患者17小时尚未能完成修复。

基于硝酸盐缓释-功能微生物协同的污染底泥原位修复技术研究

重污染底泥原位修复常需外加大量电子受体,但大量实践表明电子受体直接投加存在作用时效短、微生物利用效率低等问题.针对该问题,开发了电子受体缓释-功能微生物协同的复合环境功能材料,并探讨了功能材料对底泥原位修复效果.结果表明:①复合功能材料〔以Ca(NO 3)2计,下同〕仅投加5.7 g/kg时,底泥中ORP(氧化还原电位)提升了60.17%~73.96%,AVS(酸可挥发性硫化物)去除率高达90%,是其他传统原位修复材料的1倍.②相较于单独投加Ca(NO 3)2的修复方式,复合功能材料最大可去除上覆水中33.78%的ρ(TN),而且ρ(NH4^+-N)也降低了27.90%.③复合功能材料同时促进上覆水中TP和COD Cr的去除,其去除率分别在78%和30%以上.④从经济成本和对环境影响的角度出发,在工程应用上宜用电子受体∶固定剂∶促凝剂∶发泡剂∶塑形剂∶复合微生物菌剂∶水的质量比为1∶5∶0.5∶0.5∶0.1∶1∶1的复合功能材料.研究显示,硝酸盐缓释-功能微生物复合材料是一种高效的重污染底泥原位修复材料,能显著提升底泥和上覆水中污染物去除效率,降低ρ(NH4^+-N)、ρ(COD Cr),避免上覆水体受到二次污染.

河道污染底泥修复与处理技术探讨

搞要:河道底泥中积累的大量污染物质作为二次污染源严重影响了水体环境。文章分析了底泥的主要污染物种类,系统地介绍了各种处理技术及资源化利用途径。目的是在实现底泥减量化、无害化和资源化利用的同时探索出一条适合我国国情的经济有效型、环境友好型的底泥可持续发展道路。

河道底泥处理和处置现状及发展研究

河道中的底泥组分复杂,容易受到有机物、重金属和氮磷等的污染。随着社会的发展和进步,污染底泥的处理越来越受到关注。目前,河道底泥修复分为原位修复和异位修复两种,异位修复比较常见。原位修复中的物理、化学、生物方法具备绿色、可持续的优点,特别是新研发的联合修复技术近些年引起广泛关注。所以,本文分析了国内外常见的几种底泥处理方式并提出了今后发展的方向。